The invention relates to apparatus for processing and packaging products, and specifically to a yield monitoring system in apparatus for slicing and/or packaging foodstuffs.
The ever-accelerating pace of modern life has caused consumers increasingly to rely upon pre-packaged food products. In order to meet consumer expectations and other requirements, modern food processing and packaging systems are geared toward providing products that are consistent in size, weight, and appearance. An example of such systems may be seen in U.S. Pat. No. 5,109,936 to Ruppel. This known system includes a slicing machine having a slicing blade and a feed mechanism, and uses feedback from primary and secondary weighing systems to control slice thickness. Another example may be seen in U.S. Pat. No. 3,846,958 to Divan. In this system, out-of-tolerance drafts are diverted to another location in order that an attendant may add or subtract product to make proper weight. Each of these patents is incorporated by reference herein. Common to all such systems is the fact that food products leaving the slicer are evaluated for weight, density, etc., and then slices of product are either adjusted, added, or taken away to achieve uniformity.
Such consistency does not, however, come without a price. Since foodstuffs such as meat naturally vary in shape, density, etc., the production of packaged foods having a predetermined, uniform size, weight, and shape increases the potential for waste. End pieces, irregularly shaped drafts, and other natural non-uniformities present costly reductions in overall product yield. That is, the amount of product input into the packaging system may greatly exceed the amount of packaged product output.
It has previously been proposed that excess product be reintroduced into the system to supplement drafts that are underweight. One example of such a "makeweight" component is set forth in U.S. Pat. No. 5,499,719 to Lindee et al., which is hereby incorporated by reference herein. In order to minimize waste, this system corrects any out-of-tolerance or "reject" food product groups. The corrected groups of food slices or other food products can then be put into the stream of originally correct groups and sent on to a packaging location or other utilization position.
Undoubtedly, such makeweight arrangements increase the overall efficiency of the food product processing systems. However, while the above-described systems present various approaches to quantifying the uniformity of the packaged product, they fail to address the quantification of system efficiency, i.e., system yield.
The present inventors have recognized that a need exists for an automated system to determine and monitor the overall system yield of a food processing system. Typically, all companies that calculate system yield first calculate the "weight in" of the material to be sliced. This is generally done by weighing each rack of meet on a floor scale, subtracting the weight of the rack itself, then stripping the casing and weighing that is well. This is then subtracted from the initial weight measurement to arrive at the requisite "weight in".